package web

import (
	"fmt"
	"net/http"
	"time"

	"daili/internal/domain"
	"daili/internal/store"
)

type screenDay struct {
	Date    string
	Day     int
	InMonth bool
	IsToday bool
	IsPast  bool
	Due     int
	Heat    int
}

type screenData struct {
	Stats       *store.Stats
	MonthTitle  string
	Year, Month int
	Weeks       [][]screenDay
	Weekdays    []string
	Top         []SubView
	DueToday    []SubView
	TodayList   []SubView
	Recent      []store.Adjustment
	TodayTasks  int
	TodayDone   int
	Refresh     int
	Version     string
}

func (s *Server) handleScreen(w http.ResponseWriter, r *http.Request) {
	today := domain.Today()
	warn := s.warnDays()
	stats, err := s.db.ScreenStats(today, warn)
	if err != nil {
		http.Error(w, "读取大屏数据失败", http.StatusInternalServerError)
		return
	}
	data := &screenData{
		Stats:      stats,
		MonthTitle: fmt.Sprintf("%d 年 %d 月", today.Year(), int(today.Month())),
		Year:       today.Year(),
		Month:      int(today.Month()),
		Weekdays:   []string{"一", "二", "三", "四", "五", "六", "日"},
		Top:        subViews(stats.Top, today, warn),
		DueToday:   subViews(stats.DueTodaySubs, today, warn),
		Refresh:    s.screenRefresh(),
		Version:    s.cfg.Version,
	}
	if len(data.DueToday) > 6 {
		data.DueToday = data.DueToday[:6]
	}

	// 本月热力
	monthStart := domain.MonthStart(today.Year(), today.Month())
	monthEnd := domain.MonthEnd(today.Year(), today.Month())
	gridStart := domain.AddDays(monthStart, -domain.WeekdayIndex(monthStart))
	weeks := (domain.WeekdayIndex(monthStart) + monthEnd.Day() + 6) / 7
	for wi := 0; wi < weeks; wi++ {
		week := make([]screenDay, 0, 7)
		for di := 0; di < 7; di++ {
			d := domain.AddDays(gridStart, wi*7+di)
			ds := domain.Date(d)
			due := stats.Heat[ds]
			week = append(week, screenDay{
				Date:    ds,
				Day:     d.Day(),
				InMonth: d.Month() == today.Month(),
				IsToday: ds == domain.Date(today),
				IsPast:  d.Before(today),
				Due:     due,
				Heat:    heatLevel(due),
			})
		}
		data.Weeks = append(data.Weeks, week)
	}

	if adj, err := s.db.RecentAdjustments(6); err == nil {
		data.Recent = adj
	}
	list, done := s.todayTaskList(today)
	data.TodayTasks = len(list)
	data.TodayDone = done
	data.TodayList = subViews(list, today, warn)

	p := s.newPage(r, "大屏", "screen")
	p.D = data
	s.render(w, r, "screen", p)
}

// todayTaskList 返回今天应服务的订阅与已完成数量。
func (s *Server) todayTaskList(today time.Time) ([]store.Subscription, int) {
	ts := domain.Date(today)
	subs, err := s.db.CalendarSubs(ts, ts)
	if err != nil {
		return nil, 0
	}
	ids := make([]int64, 0, len(subs))
	for _, sub := range subs {
		ids = append(ids, sub.ID)
	}
	pauses, _ := s.db.PausesForSubs(ids)
	checkins, _ := s.db.CheckinsBetween(ts, ts)
	warn := s.warnDays()
	out := []store.Subscription{}
	done := 0
	for _, sub := range subs {
		if sub.Status == domain.StatusClosed {
			continue
		}
		if sub.StartDate > ts || sub.EndDate == "" || sub.EndDate < ts {
			continue
		}
		cs := calSub{sub: sub, pauses: pauses[sub.ID], hasEnd: true, eval: sub.Eval(today, warn)}
		if sub.Unit == domain.UnitCount && cs.eval.RemainingCount <= 0 {
			continue
		}
		if cs.pausedOn(ts) {
			continue
		}
		out = append(out, sub)
		if ci, ok := checkins[sub.ID][ts]; ok && ci.Status == "done" {
			done++
		}
	}
	return out, done
}